The invention is based on a hydraulic vehicle brake system. Such hydraulic vehicle brake systems having two separate brake circuits, a brake booster, an anti-skid system and hydraulic energy supply systems to supply them, are known, for example from German Offenlegungsschrift No. 30 40 562. There, a brake booster is provided in a housing and is followed by a tandem cylinder arrangement. Located in this tandem cylinder arrangement is a restoring ring plunger, which when the anti-skid system is actuated displaces the cylinder plunger back against the brake pedal, via elements of the brake booster. The piston chamber formed by the restoring ring plunger, the cylinder plunger and the housing communicates exclusively with the supply container, so that the feedback on the brake pedal via the restoring ring plunger is not controlled in any way. Depending on the circumstances when regulated operation--that is, the anti-skid regulation--is initiated, this feedback may be very strong and may be unpleasant for the driver. Moreover, no provision is made in this apparatus for refilling brake fluid into the brake chambers.
Throttle devices especially for damping the pedal return motion are known, but they are subjected to brake fluid flowing through them both in normal braking and during regulated operation. These throttles have the disadvantage that they become plugged-up, from a steady deposition of foreign particles. This defect goes unrecognized by the driver, yet the safety of the brake depends on the reliability of the throttle device. Once the throttle is plugged, the plungers cannot be moved into the intended safety position during braking with the anti-skid system. If the energy supply then fails, the vehicle can be braked only with reduced residual braking action, if at all.